Yamaha FZ-07/MT-07/R7 698.29cc Overbore High Compression Piston Kit-80.5mm

Description

Spears Racing Overbore High Compression Piston Kit-80.5mm kit 698.29cc includes pistons, rings, lighter wrist pins, cir clips . The compression is 13 to 1. Dome features smooth flowing radius, under crown machining to lessen the overall weight, Acc Grooves, Double pin oilers,Double Brooch Grooves for extreme applications including professional competition.

Spears race pistons with the State of the Art CNC Machining and manufacturing alliances with JE Pistons for decades. Spears Racing continuous committed to excellence to advance as the industry changes. This commitment has resulted in more forgings specific to certain applications, proprietary treated wrist pins and piston rings manufactured only for us. Each of these aspects has been put through stringent research and development stages to ensure that our product will exceed your standards.

At the forefront of performance, piston manufacturing has been a result of continuous research and development of unique materials, piston designs and technologies. Utilizing State of the Art CNC machines for manufacturing, along with purpose-designed forgings, while being able to maintain exacting specifications on each and every piston – holding tolerances to millionths of an inch

The Spears Racing branded piston (Preferred Performance) have been winning races and Championships all over the world for over 4 decades. Spears Racing pistons have been in several of the race wins in close course racing and in road circuits in Europe and has won the Isle Of Man TT Twins several times.

Spears Racing Piston Kits for the Yamaha FZ/MT07 and now the R7 have been the piston of choice by several race teams around the world.

Overbore Pistons FZ07/MT07 Piston Terminology for Spears Racing Pistons:

ANTI DETONATION GROOVES (CONTACT REDUCTION GROOVES) Also know as contact reduction grooves, which limit the piston/cylinder contact during high temperature and high RPM. These grooves also protect the top ring by disrupting detonation waves

ACCUMULATOR GROOVE V-shaped groove machined in the 2nd ring land that adds to the volume between the top and second ring. This groove accumulates residual gasses from combustion which alleviates top ring flutter and premature second ring wear, improving ring seal.

PIN FITTING The pin bore is precision honed to attain an exact pin clearance. Depending on the application clearances typically range from .0003 to as much as .003 between the wristpin and bore.

“Preferred Performance” Pistons Kits By Spears Racing

What are Piston Terms

Spears Racing’s High Compression Overbore High Compression Piston Kit-80.5mm 13.0 to 1  Includes the Following:

Large Valve Pockets for 1mm over valves (Each Piston dome is complete deburred /Brushed to knocked down to have no Sharpe angles to create hot spots)
Pistons x 2
Wrist Pins x 2
Piston Rings x 2
Cir Clips x 4

Piston Weight:217 grams